The present invention relates to a container wherein the volume of the container can be varied so as to minimise the amount of air in the container.
Containers are generally of fixed volume. It is usually necessary to have a number of containers of different sizes as it is well known that food will last longer if its contact with air is minimised. Also having containers larger than is necessary sometimes presents a problem, especially when space is at a premium.
Another problem often encountered is that of aerated drinks going xe2x80x9cflatxe2x80x9d or losing carbonation when stored. This is a result of the gas escaping from the drink into the neighbouring air.
It is an object of this invention to provide a container having a variable volume which will attempt to overcome the above disadvantages, or which will at least provide the public with a useful alternative choice.
According to one aspect of the present invention there is provided a container comprising an inner flexible member substantially enclosed in a number of inseparable and interlocking outer sleeves, wherein the volume of the inner flexible member container can be varied by moving at least one outer sleeve relative to another outer sleeve.
The outer sleeves remain inseparable during normal telescoping operation and can only be separated by the User via a mechanism for this express purpose.
The interlocking sleeves can be screw threaded together so that by twisting the sleeves relative to each other the volume of the member can be varied.
The interlocking sleeves can alternatively move relative to each other by means of a ratchet. An upper sleeve can include at least two series of externally projecting teeth. A handle on a lower sleeve can be provided to act as a pawl for each series of externally projecting teeth. To decrease the volume of the container, the upper sleeve can be pushed downwards towards and into the lower sleeve. To release the sleeves and hence to increase the volume of the container, the handles can be used, or the upper and lower sleeves can be rotated relative to each other.
The interlocking sleeves can alternatively move relative to each other by means of a multi-level bayonet connection. The multi-level bayonet connection alternatively is formed by providing in either an upper or lower sleeve opposed grooves, each set of grooves comprising a plurality of transverse grooves connected by a longitudinal groove. At least two pin members can extend from the adjacent lower sleeve or upper sleeve to fit one into each set of grooves in the other sleeve. Rotation of the upper and lower sleeves causes the transverse pins to move in the transverse grooves to the longitudinal groove and hence to vary the volume of the container in a push/pull and twist action.
The inner flexible member can be fixed to the base of the lower sleeve by means of a pin. The inner flexible member can be welded to the upper sleeve.
Alternatively, a lip of the inner flexible member can protrude through an opening in the container, hence providing a seal between the inner flexible member and a cap. This allows the inner flexible member to be removed completely from the outer sleeves.
The inner flexible member can be concertina or balloon-like.
The container can be sealed by means of the cap, the cap including a threaded skirt with a float mounted therein. The float has a skirt mounted thereon or formed integrally therewith and a button section. As the volume of the container is decreased by moving one outer sleeve relative to another outer sleeve, air can escape through a passage between the outer edge of the skirt and inner surface of the cap and threaded skirt. Once a liquid or other flowable material reaches the float, the float rises, gradually shutting off the escape of air when the skirt contacts the inner surface of the cap.
According to a further aspect of the invention, there is provided a variable volume container comprising an exterior casing with an inner flexible bladder, the internal volume of which is adjusted by moving one end of the bladder by any suitable means so that in use the volume of the flexible bladder and the volume of its contents are substantially the same.